Hypertrophied myocardium is more dependent on extracellular calcium than the normal cardiac muscle
| Autor: | Barros, R., Zornoff, L. A. M., Ribeiro, H. B., Okoshi, M. P., Carlos Roberto Padovani, Aragon, F. F., Cicogna, A. C. |
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| Přispěvatelé: | Universidade Estadual Paulista (UNESP), Universidade Estadual Paulista (Unesp) |
| Předmět: |
chloride
beta adrenergic stimulation animal experiment Wistar rat animal tissue heart function male heart contraction heart performance Papillary muscle calcium ion controlled study rat Myocardium function Renovascular hypertension heart muscle fiber membrane steady potential Calcium isoproterenol calcium cell level isoprenaline heart ventricle hypertrophy nonhuman concentration (parameters) muscle isometric contraction animal model heart papillary muscle inotropism extracellular calcium heart muscle relaxation |
| Zdroj: | Scopus-Elsevier Scopus Repositório Institucional da UNESP Universidade Estadual Paulista (UNESP) instacron:UNESP ResearcherID |
| Popis: | Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:24:46Z No. of bitstreams: 0 Made available in DSpace on 2014-05-27T11:24:46Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-08-13 Background: The aim of this study was to analyze stable hypertrophied myocardial function and its response to inotropic maneuvers in rats submitted to renovascular hypertension for a 10-week period (RHT group, n=10). Material/Methods: Myocardial performance was studied in isolated left ventricle papillary muscles in isometric contraction under the following conditions: at postrest contraction of 30 seconds (PRC), at extracellular calcium (ECa 2+) chloride concentration of 1.25 and 5.20 mM, and after beta-adrenergic stimulation with 10 -6 M isoproterenol (ISOP). Results: The results were compared with normotensive Wistar controls rats (C group, n=10). In basal condition, resting tension, and contraction time (TPT) were greater, while relaxation time (RT 50) tended to be longer in RHT than C group. PRC and ISOP promoted a similar change in muscle function response intensity (Δ) in both groups. ECa 2+ shift did not change TPT in the C group and decreased TPT in the RHT animals; Δ was different between these groups. RT 50 increased in C and decreased in RHT, both without statistical significance; however, Δ was different. Conclusions: These results suggest that hypertrophied myocardial dysfunction may be attibuted to changes in intracellular calcium cycling. © Med Sci Monit, 2010. Botucatu Medical School UNESP - São Paulo State University, Botucatu Botucatu Medical School UNESP - São Paulo State University, Botucatu |
| Databáze: | OpenAIRE |
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